


An unforgettable birthday

by AzureDarknessYugi



Category: Final Fantasy XIII
Genre: Anal Fingering, Birthday Sex, Classroom Sex, Cross-Posted on FanFiction.Net, F/F, Farroncest - Freeform, First Time Blow Jobs, Futa-Lightning, Futanari, Loss of Virginity, Yuri
Language: English
Status: Completed
Published: 2015-05-14
Updated: 2015-05-14
Packaged: 2018-03-30 13:29:57
Rating: Explicit
Warnings: Underage
Chapters: 1
Words: 3,952
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/3938554
Author URL: https://archiveofourown.org/users/AzureDarknessYugi/pseuds/AzureDarknessYugi
Summary: <blockquote class="userstuff">
              <p>It's Serah's 18th birthday and Lightning is going to give her a birthday that Serah's not ever forget.</p>
            </blockquote>





	An unforgettable birthday

**Author's Note:**

> This was originally posted on Fanfiction and moved to here. Also, if you don't like futa don't read this story. If you do, enjoy. Feedback is welcomed.

After a long stressful day at school. Serah hurried home for a special birthday dinner with her big sister\girlfriend. She was turning 18 today and, Lightning said she'll give her something very  _special_ on her birthday. Serah happily thought back when they first kiss and, the first time they had sex 3 years ago.

* * *

It was the day of Lightning's high school graduation. They visited Lightning's classroom cause it had a great view of the fireworks being held for the grads. Serah is going to miss seeing Lightning in the boy's school uniform. It consisted of; black school jacket with the school's symbol on the front right, white dress shirt with a black tie, black dress pants, and black shoes. She looked very handsome in it. Especially when Lightning has her jacket open and shirt hanging over her pants.

She wasn't the only one who thought that. Lightning would always get love letters from the other girls. Serah didn't like that like very much. Doesn't know why, though. Seeing her big sis leaning on her desk with hands in her pockets, and how the lights from the fireworks reflecting off those pale blue eyes. The sight made the young schoolgirl blush, and her heart starting to race. This happens to her sometimes when the were alone together. It hit her.

Had she fallen in love with her own sister? Serah knew this was wrong, but she couldn't help it. Lightning was always there for her. Protecting her, supporting her, and caring for her whole life. Serah viewed her Lightning less of a big sister, and more of a guardian, a knight, a prince.

Feeling her younger sister's gaze, Lightning turned her head towards Serah and asked with slight concern in he voice. "Are you all right Serah? Your face is all red."

Serah flinched by her sister's words. " _All right!_   _I'm going to tell her!"_  Serah thought to herself. Steeling herself walked closer to her big sis. With each step, her heart beat faster and faster. When she at face-to-face distances. Serah swallowed hard and cupped her sister's face. Looking deep in her eyes. "I love you, Claire." Lightning's eyes widen and cheeks turn red with her words. This isn't the first time she's heard that she heard those words. Hearing it from the other girls. She never got the chance to say anything back to the girls. Cause Serah always pull her away before she can say anything. Having a hint of jealousy in Serah's expression.

Lightning heard her little sister say those three words numerous times, but now it sounds different. "Serah when you say you love me. You mean more than just as your sister?" Lightning asked.

Serah nodded and her eyes were full of love. "Yes, you're my first crush after all. It just took me awhile to realize it." Lightning's heart jumped when she heard those words. Pulling her hands out of her pockets, and place them on Serah's waist. Serah moved her hands, through Lightning's soft and silky rose coloured hair. Pulling each other closer so their lips were just about to touch.

"I love you to Serah. With all my heart. Always have and always will." The younger sister's heart was full of joy, as Lightning felt the same way.

Lightning pressed her lips on her sister's, their bodies heated up as they share their first kiss. Serah was happy that her first kiss was Lightning. The sisters started to suck and licking each others lips. Serah wanted to taste more of her big sis snaked her tongue into Lightning's mouth, and she happily accepted it.

Both sisters started to moan in pleasure as a dance of tongues began in their mouths. Each gets hooked on each others taste. Lightning moved her hands down and garbed Serah's ass. She let out a cute moan into Lightning's mouth. Serah could tell Lightning is getting turned on, cause she can feel her sister getting hard against her. Serah moved her hips so Lightning's dick would grind against her.

Lightning pulling away from the kiss, leaving a trail of saliva. "S-Serah?! W-what are you-"

Serah cut her off by moving her right arm down and rubbed Lightning's crotch. "You feel so  _hard_  and so BIG, Claire. Let me help you with that." She got on her knees and undid Lightning's belt then unzipped her pants.

Lightning couldn't believe it, her little sister is about to give her a blowjob. "Do you know, w-what are doing?" Lightning said in a panic. Serah pulled down her sister's boxers and saw Lightning' stiff erection. It was a lot bigger than the she fantasized.

"No, but I have been reading about it. So I'll try my hardest for you. Okay,  _big_  sis?" Serah said sexually.

It's very rare for a girl to be born with a dick. Sometimes one can be born with both girl and boy parts. But Lightning is 100% man down below. Complete with a lovely set of big balls. Serah started licking the head of Lightning's dick and stroked it with her right hand while rubbing herself with the left. Lightning tightens her grip on her desk; as she never felt any like this before. Seeing Serah licking and stroking her cock turned her on. Serah peeled back the foreskin revealing the head of Lightning's dick. Seeing her sisters' cock in it's full glory made her very wet.

Serah saw liquid coming out her big sister's cock. She heard about this in her books and mangas. It's called pre-cum, meaning Lightning is enjoying it. Happy about this, She wondered what her sister's pre-cum will taste like. So she sucked the tip of her sis's cock, hearing her sister's moans as she did this.

Wanting to hear more; Serah lifted Lightning's cock and lick the backside. Then sides and every inch of her sister's delicious cock. Serah then moved down and sucked on Lightning's tasty balls, while stroking it at the same time.

Lightning was lost in a wave of pleasure. Her mind going crazy. "S-Serah... Put it in your mouth.." Lightning requested. Obediently, Serah wrapped her mouth around Lightning's big cock. The smell and taste of her sister's cock clouded her mind. Serah moved her head back and forth with lust and passion. Serah went deeper, and faster until she took it all in.

She moved her fingers faster inside her, as she sucked off Lightning. "That feels good my dear Serah. Keep going." Lightning growled. Feeling her body getting very hot and sweaty. Lightning took off her school jacket, tie and unbutton her long sleeved shirt. Letting some cold air touches her hot sweaty body.

All that Serah could think about is Lightning and her big cock in her mouth. " _Oh, Claire... Your cock tastes so good."_ Serah thought lustfully.

Getting weak in the knees, Lightning felt like she about to explode. "SHIT! I'm about to c-cum! Take it all... Okay?! " Lightning grabs the back of Serah's head and let out her seed in Serah's mouth.

Serah came as she felt Lightning's cum flow into her mouth. She drinks all of her sister's rich cum. "Mmm..delicious." she said licking cum off her lips. Looking up, she saw that Lightning had open her shirt. Serah can see Lightning's black and red sports bra and her developing abs.

Lighting helped her sister up and, moved hands down then lifted her by the ass, turned Serah around and placed her on Lightning's desk. "C-Claire what are doing?" Lightning gave her a mischievous smile and started licking Serah's neck.

"I'm repaying a favor." Serah's whole body trembled when she felt her sister's tongue traveling all over the side of her neck. Suddenly, Lightning started sucking on her neck. Serah tightening her grip on Lighting's shirt.

She couldn't believe just having her neck sucked can feel so good. Lightning slid her hands under Serah's shirt and fondled her soft breasts. Serah pulled down Lightning's shirt as she felt her breasts being touched. Moaning in pleasure. Lightning release her lover's neck from her mouth, leaving a kiss mark behind.

Lightning lifted Serah's shirt and place it in her mouth. "We don't want anyone to hear you and interrupt us right?" Serah nodded in agreement. She undid Serah's bra in the front then started sucking on her right nipple while rubbing the left. Serah can she feels breasts getting hotter as the older sister continued, sucking on her nipple like a hungry baby. She switched nipples and did the same on the other one.

"Did that feel good?" she said finally let go of her tits. Serah nodded. "Good, but we're not done yet." Lightning spread Serah's legs and moved down to her pussy. Serah can feel her face growing redder, as she saw her sister's head disappear under her skirt.

Lightning saw how soaked Serah's panties are. "My Serah! You're so wet." She pulled her sister's panties down and set Serah's legs on her bare shoulders. "You have a pretty pussy Serah." Lightning licked the outer edge of Serah's pussy. The sweet aroma of her sister's pussy is driving her wild.

With her thumbs, she spreads Serah's lips and stuck her tongue in. Lightning moved her tongue in a slow circle. Serah moaned when she, felt Lightning's tongue moving around inside her. She can feel Serah getting tighter around her tongue. It was so tight that she can only, move back and forth. So she did just that. She loved the taste of Serah's pussy with her tongue.

Having her big sister eating her out, was like a dream come true. She can feel herself about to cum. Suddenly she felt Lightning's finger going into her ass and, she let out an adorable moan. Lightning took out her tongue and focused her addition on her sister's clit. Serah's legs tighten around Lightning's head and grab her soft silky hair.

After a few minutes, she squirted in Lightning's mouth. The older sister drank every single drop of her younger sister's sweet honey. Serah let her shirt out of her mouth, her mind filled with pleasure. "Amazing." Serah said in a daze. Lightning licked the remaining juices from her fingers and mouth.

While looking at Serah with a lustful look in her eyes, finding this act really sexy. Lightning felt her dick getting hard again got up and, lined herself in front of Serah's wet entry. "This is going to hurt, okay?" the younger sibling knew what's going to happen. She was going to give her first time too, her dear older sister.

Serah nodded and braced herself when she felt Lightning, slowly entering her. Stopping before entering her hymen. "Ready Serah?" she gave one more nod. "If I'm going to give my virginity to someone. Who better than the love of my life." hearing those words, Lightning moved and broke through. Serah muffled her cry of pain. Lightning kissed Serah deeply to help her to get over the pain. They kissed until Serah adjusted to Lightning's cock.

She warped arms around the older Farron's neck. "You can move now." Serah said between kisses. Lightning kept kissing Serah as, she pumped her hips to muffle her moans. Feeling Lightning's dick going back and the fourth side, she sends her into a world of pleasure. Lightning can feel Serah getting tighter around her dick.

"You know Serah... I heard that have sex with the one you love... Feels so very good. "

"I guess it's true. Cause your cock feels so good inside me and, I love you so very much."

The grad student was trying not to move her hip so much because, it will make Serah moan too loudly. But her hips had a mind of its own, and her own mind was starting to fog. "I can't take it anymore! You just feel so fucking so GOOD Serah!" this the first time Serah heard, Lightning's voice sounding very sweet. Most likely she lost herself to pleasure.

Unable to keep her moans back anymore, Serah let them out. "AHHH! Claaaire! I'm going to cum! Cum with me Claire!" With one final push, Lightning released her hot seed, causing Serah to climax as well. They let out a synchronized orgasmic scream. Lightning garbed the edges of her desk to keep herself standing. "That was amazing.  _Big_ sis." she laughed lightly at her little sister's comment. Serah gave Lightning gave her big sister a warm embrace. From that day, forth their relationship grew from sisters to lovers.

* * *

That was one of Serah's most treasured memories. The day, when they became lovers, was the happiest day of her life. Finally reaching her house, she can hear her favorite song playing from the inside. Opening the door, she found Lightning getting her birthday dinner ready. Serah's face went bright red, by what her lover was wearing. Lightning was wearing a long three tailed blue coat, a black scarf tucked in a similarly coloured vest, brown fingerless gloves, black pants, and dark brown knee high boots. She even had her hair slick back and tied it into a ponytail. Lightning looked rather regal in it.

"I kind of like this. I should wear this on my days off." Lightning said as she checked out the clothing she had on.

The idea of Lightning wearing that more often. Appealed to Serah very much. "YES YOU SHOULD! YOU LOOK TOTALLY HOT IN THAT!" Serah shouted happily.

Lightning chuckled and moved closer to her dear girlfriend with hands in her pockets. "Well if that's what you want, then I will." she said softly as she lifted Serah's chin slowly. Lightning looks at Serah with a lustful gaze. Oh, how she loved that look in Lightning's eyes. A look only meant for Serah and Serah alone.

Those pale sapphire eyes matched perfectly with her new jacket.

Lightning offered her hand to lead Serah to the dinner. Serah was happy at the fact that Lightning only showed, this side of her. When she's around Serah. The young lover happily accepted her girlfriend's hand. And she leads to a gorgeous dinner set-up.

It did look more like a romantic dinner than a birthday one. "Where did you buy all of this? " Serah said in amazement, knowing Lightning is not really good at cooking.

"Hey." the soldier said, sounding offended.

"Sorry Claire, it's just it's a looks so good and you even got my absolute favorite cake. I love it. Thank you!" she gave her lover a quick peck on the cheek.

This made Lightning blush a bit. "W-Well I'm glad you like it. Like this outfit, it wasn't cheap." Serah absolutely LOVED this part of her too. Lightning pulled a chair back and sat her lover down in front of the birthday cake. "Make a wish." Serah knows exactly what she goes to wish for.

As Lightning was cutting the cake, Serah asked. "How did you know, I want you to see you in that?"

The soldier gave a warm smile. "You know that clothing store we pass sometimes?" Serah nodded. "You keep looking at this, every time we pass by. So, I bought it." Lightning gestured at her new clothes. Serah was both happy and embarrassed. Happy that Lightning was sweet enough to get it. But embarrassed that she caught her eyeing that outfit.

The two lovers began eating dinner. They talked about their day, and Serah asked Lightning how she got her hair like that. Lightning explained she just raked it back and tied it into a ponytail. There's is no way its that simple. So Serah ruffled Lightning's hair and wanted her to prove it. And she did. With one hand, she slicked her hair back like magic. Serah clapped her hands in amazement.

After eating the cake and food. They made their way up to the bedroom. "It's time for your  _present_ Serah." She has been waiting for this moment. Finally, she'll have Claire all to herself.

The young Farron held her dearest arm tightly. She can feel the warmth in her beloved's arm through the coat. Surprising Claire. Serah pushed her lover down hard on the bed. Not caring that they're still wearing shoes.

Not having the time to react, she felt Serah's lips on her own. Serah sucked and licked at Claire's lips with great hunger, lust, and want. Claire opened her mouth and let Serah's tongue in. Their tongues twirled in their mouths. Serah moaned loudly into Claire's mouth. She grabbed Claire's breast and squeezed and rubbed them. This made, the older lover moan a bit more load.

Serah slowly unzipped Claire's black vest and untied her scarf. Revealing her six pack ads. She always gets turned on when she sees Lightning's sexy abs. Serah moved her hands over what she thought was Claire's sports bra. But was surprised to feel a lace-like fabric. She broke the kiss and looked down and saw that she's wearing a red lace bra. "You said you wanted to see me in one." she looked to the side and her face turning red.

Serah can't get enough of Claire's hidden cuteness. She discovered that her lover's new bra can undo from the front. Claire's breast bounced as they are released from their restraints. She's glad that her girlfriend has both female and male parts.

The young lover placed her mouth over Claire's left nipple and squeezed her right. "Ahh... W-Where did ahh... You learned to do that." Claire asked, her voice growing sweeter.

"From you." Serah said while moving to the other nipple. She remembered all of the trough lovely time when Claire would suck and play with her breasts. The way, she did it, would make Serah cum instantly. And now she is doing it back to her loving big sister. She can tell that her girlfriend's nipples are getting hard and something else getting harder too.

She knew it's time and slid down and unbuckled Claire's belt. Then she pulled down Claire's pants and boxers, letting her throbbing hard-on bounced up. Serah mouth water by the sight of Claire's cock. Unable to fight her urge anymore.

Serah lustfully put her mouth around Claire's cock. "AH..SHIT!" the soldier gasped, at the sudden feel of Serah's mouth. It sends her straight over the edge. Over the years, Serah learned all of Claire's weak spots. Also, her mouth became like a vacuum cleaner. She sucked, licked until Claire was about to ejaculate.

But suddenly stopped. "Serah... Why did you stop." Claire moaned.

Serah smiled seductively. "Because, I want you to cum in  _here_." She lifted her hips up and moved her panties to the side. Moving her hips down slowly, until she felt Claire's cock entered inside her. She can feel a course of electrically goes through her body.

Slowly she lowered her hips until it hit her core. Serah had forgotten just how  _big_  her sister is. "A-Are you all right my love?" Claire gasped

"Ya, I just LOVE having your big thick cock inside me." Serah smiled at the love of her life.

Claire pulled Serah closer to giving her a passionate kiss. Claire can feel her sister getting tighter around her as if not wanting to let go. Not able to take it anymore she grabbed Serah's ass and moved her hips underneath her. "It feels so good!" Serah moans in pleasure. Claire wanted to hear more of Serah's moans, moved her hips faster and harder. Hitting Serah's G-spot. "MORE..CLAIRE AHH...FUCK ME MORE!" Serah screamed in total bliss.

Serah's eyes rolled back and, drool dripping down her mouth. Claire unbuttoned Serah's white sleeveless shirt. She moved her hands under Serah's bra and played with her hard nipples. This cause Serah to shout her name in pleasure. Serah closed eyes and just feel, her lover's cock ravaging inside her. It's a wonderful feeling.

The older Farron feels like she's about to explode. "S-Serah... I'm going to... Cum." Serah leaned down and hugged her lover's head. Messing up her hair again.

"Me...to sis ahh... Let's cum together." Clair moved her hands to her back and held her tight. Claire came hard inside Serah. Feeling Claire's hot seed erupting inside her. Gave Serah the biggest orgasm in her life.

"That's the greatest gift you... Have ever given me." Serah panted in Claire's ear. Smiling Lightning placed her hand on her beloved's head.

"I know you'll like it... Up for one more?" not getting a chance to respond, she was thrown to back, with Claire on top of her.

Feeling hot Claire slowly removed her black scarf, jacket and vest. Seeing Claire's sweaty muscles turned her on. She motioned her hands to Claire's back, pulling her closer for a kiss. As they kissed, Claire plunged herself back into Serah. Their kiss grew more passionate. "Fuck me hard, Claire." Serah said in between kisses. Granting her sister's wish; Claire pumped her hips as fast and hard as she could. Serah screamed in pleasure and wrapped her legs tightly around Claire's waist. Hearing Serah say her real name over and over, in her ear was turning her on. She clenched her grip on the bed sheets.

"FFuck..h-how can you..be this tight!"

Serah kissed her lover's cheek and whispered sweetly in her ear. "Because you feel soo good inside me." her words send shivers down her spine. The Farron sisters' minds went blank, with all the pleasure they're feeling throughout their bodies. Loud moans of pleasure filled the bedroom. Serah moved Claire's head so they're face to face.

The expression, she saw on Claire's face, looked like she's going to cum. "N-Not... Yet Claire... l-little bit longer okay." She nodded.

"I'll try, but you feel so FUCKING GOOD!" Claire was going crazy. Her hips have been moving on its own. Her mind going blank and the only thing she can think about; is Serah.

The same can be said for Serah. She loves fucking her dear Claire. Because of her job in the Guardian Corps. They weren't able to spend that much time together. Which was a good thing and a bad thing. Bad because she missed Claire very much. Good, because when she comes back from work, she gets  _very_  sexually frustrated. And Serah is more that willing to help her with that.

Serah can tell Claire can't hold any longer. So Serah moved Claire's head to her breasts. "Suck on them. You know much I like it." Serah said in a sexual tone. Without saying a thing, Claire hungrily sucked on her nipples "YESSS! OH, GOD YES! HARDER!" Serah screamed.

"I'm going to cum again!" Claire growled.

"Me too!"

Both Farrons screamed each other names at the top of their lungs. Claire released every drop of her cum deep inside Serah. Claire rested her head Serah's chest. "Wow, that's your biggest load yet." Serah said, hugging Claire's head.

"Ya... I.. Have been.. Saving up.. Just.. For.. You." She sounded sleepy.

Serah kissed and patted her head, "You were absolutely amazing tonight. Get some rest, okay?"

But before she did that. Claire rolled over to the side. Knowing she's a bit heavy because of the muscles she gained. Serah giggled that even though Claire is very sleepy, she still has enough energy to worry about her. Serah snuggled close to her dearest. "Your clothes are going to smell like sex in the morning." Claire mumbled.

Serah laughed. "It was worth it. Now get some sleep. All right?" Lightning nodded and fell into a deep sleep.

Serah wondered if Claire will be up for some anal in the morning. She just has to ask her when she wakes up. For now She'll sleep peacefully knowing she'll never forget this Birthday.


End file.
